Generally, a bearing is a device disposed between a rotational element and a nonrotational element to facilitate rotation of the rotational element. Currently, a variety of bearings such as roller bearings, taper bearings, needle bearings, and the like are used.
A wheel bearing is a type of such bearings and rotatably connect a wheel, which is a rotational element, to a vehicle body, which is a nonrotational element. A wheel bearing comprises an inner ring (and/or a hub) connected to one of a wheel and a vehicle body, an outer ring connected to the other of the wheel and the vehicle body, and rolling elements disposed between the outer ring and the inner ring.
Since such a wheel bearing is basically mounted on wheels of a vehicle, a wheel bearing is exposed to foreign substances such as dust, water, and the like. When such foreign substances penetrate into a wheel bearing, particularly, into a portion on which rolling elements are mounted, a raceway that is a polished surface may be damaged. The damaged raceway may generate noise and vibration when the wheel bearing operates and may reduce a lifespan of the wheel bearing. Accordingly, sealing devices for preventing a penetration of foreign substances from the outside and preventing a leakage of grease and the like, which fills the raceway for lubrication of rolling elements, are mounted on one end or both ends of the wheel bearing.
The sealing device includes a slinger mounted on a hub, an outer ring, or an inner ring and a lip having a shape of protruding from the slinger and being mounted on the slinger, and performs a sealing function of sealing a gap between the outer ring and the inner ring (and/or the hub) according to shapes of the slinger and the lip. However, when the slinger deviates from an original position of being mounted on the hub, the outer ring, or the inner ring, sealing performance of the wheel bearing sealing device may be deteriorated. Also, when the slinger excessively deviates from the hub, the outer ring, or the inner ring, performance of the wheel bearing itself is adversely influenced.
Particularly, in a vehicle that a wheel is connected with the hub (and/or the outer ring), the hub (and/or the outer ring) may be instantaneously or continuously deformed by a load and a shock directly transferred to the wheel from the ground or transferred to the wheel according to a driving environment, and thus the slinger mounted on the hub (and/or the outer ring) may deviate from an original mounting position.
FIG. 1 illustrates a schematic structure of a conventional wheel bearing, and FIG. 2 illustrates a partial enlarged view of FIG. 1.
As shown in FIGS. 1 and 2, a slinger 5 press fitted on a hub 3 in a conventional wheel bearing 1 is press fitted on the hub 3 to be held by a protrusion 7 of a curved surface.
Accordingly, the slinger 5 press fitted on the hub 3 in a conventional wheel bearing 1 may go over the protrusion 7 of the curved surface by a vibration caused by operation of the wheel bearing 1 and an axial load from an external force generated by driving of the vehicle, and may deviate from an original mounting position.